https://devzone.nordicsemi.com/f/nordic-q-a/70933/jlink-v9-programmer-failed-to-update-modem-firmwareHi Nordic team Customer SecuX failed to use JLINK V9 to update modem firmware to Thingy91 and customer nRF91 board both. But, JLINK V9 can program merged.hex file(application code) to Thingy91 and customer nRF91 board both. Please double check ifen-USTelligent Community 13Tue, 26 Jan 2021 18:46:36 GMThttps://devzone.nordicsemi.com/thread/291366?ContentTypeID=1Tue, 26 Jan 2021 18:46:36 GMT137ad170-7792-4731-bb38-c0d22fbe4515:e8be4e7e-1183-444e-bda3-6528fd1b16fcKenneth<p>Can this be any of these reason?&nbsp;</p> <p><a href="https://devzone.nordicsemi.com/f/nordic-q-a/69736/nrf-connect-fails-to-update-nrf9160-dk-modem">https://devzone.nordicsemi.com/f/nordic-q-a/69736/nrf-connect-fails-to-update-nrf9160-dk-modem</a>&nbsp;</p> <p><a href="https://devzone.nordicsemi.com/f/nordic-q-a/70016/nrf-connect-on-macbook-giving-error-in-programmer-app"></a></p> <p>You can also try to download the latest j-link drivers from here:&nbsp;<a href="https://www.segger.com/downloads/jlink/#J-LinkSoftwareAndDocumentationPack">https://www.segger.com/downloads/jlink/#J-LinkSoftwareAndDocumentationPack</a>&nbsp;</p> <p>I assume you have tried to click the Erase All -button.</p><div style="clear:both;"></div>